Note: Descriptions are shown in the official language in which they were submitted.
WD 96/09370 PCT/US95/11271
' PROCESS FOR MAKING A HIGH DENSITY DETERGENT COMPOSITION WHICH
INCLUDES SELECTED RECYCLE STREAMS
' S
FIELD OF THE INVENTION
The present invention generally relates to a process for producing a high
density laundry
detergent composition. More particularly, the invention is directed to a
continuous process during
which high density detergent agglomerates are produced by feeding a surfactant
paste and dry
starting detergent material into two serially positioned mixer/densifiers and
then into drying,
cooling and screening apparatus. The process includes optimally selected
recycle stream
configurations so as to produce a high density detergent composition with
improved flow and
particle size properties. Such improved properties enhance consumer acceptance
of the detergent
composition produced by the instant process.
BACKGROUND OF THE INVENTION
Recently, there has been considerable interest within the detergent industry
for laundry
detergents which are "compact" and therefore, have low dosage volumes. To
facilitate production of
these so-called low dosage detergents, many attempts have been made to produce
high bulk density
detergents, for example, with a density of 600 g/1 or higher. The low dosage
detergents are
currently in high demand as they conserve resources and can be sold in small
packages which are
more convenient for consumers.
Generally, there are two primary types of processes by which detergent
particles or powders
can be prepared. The first type of process involves spray-drying an aqueous
detergent slurry in a
spray-drying tower to produce highly porous detergent particles. In the second
type of process, the
various detergent components are dry mixed after which they are agglomerated
with a binder such
as a nonionic or anionic surfactant. In both processes, the most important
factors which govern the
' 30 density of the resulting detergent material are the density, porosity,
particle size and surface area of
the various starting materials and their respective chemical composition.
These parameters,
however, can only be varied within a limited range. Thus, a substantial bulk
density increase can
only be achieved by additional processing steps which lead to densifcation of
the detergent
material.
There have been many attempts in the art for providing processes which
increase the
density of detergent particles or powders. Particular attention has been given
to densification of
spray-dried particles by "post-tower" treatment. For example, one attempt
involves a batch process
WO 96/09370 PCT/US95/11271
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in which spray-dried or granulated detergent powders containing sodium
tripolyphosphate and
sodium sulfate are densified and spheronized in a Marumerizer~. This apparatus
comprises a
substantially horizontal, roughened, rotatable table positioned within and at
the base of a
substantially vertical, smooth walled cylinder. This process, however, is
essentially a batch process
and is therefore less suitable for the large scale production of detergent
powders. More recently,
other attempts have been made to provide a continuous processes for increasing
the density of "post-
tower" or spray dried detergent particles. Typically, such processes require a
first apparatus which
pulverizes or grinds the particles and a second apparatus which increases the
density of the
pulverized particles by agglomeration. These processes achieve the desired
increase in density only
by treating or densifying "post tower" or spray dried particles.
However, all of the aforementioned processes are directed primarily for
densifying or
otherwise processing spray dried particles. Currently, the relative amounts
and types of materials
subjected to spray drying processes in the production of detergent particles
has been Limited. For
example, it has been difficult to attain high levels of surfactant in the
resulting detergent
composition, a feature which facilitates production of low dosage detergents.
Thus, it would be
desirable to have a process by which detergent compositions can be produced
without having the
limitations imposed by conventional spray drying techniques.
To that end, the art is also replete with disctosures of processes which
entail agglomerating
detergent compositions. For example, attempts have been made to agglomerate
detergent builders
by mixing zeolite and/or layered silicates in a mixer to form free flowing
agglomerates. While such
attempts suggest that their process can be used to produce detergent
agglomerates, they do not
provide a mechanism by which starting detergent materials in the form of
pastes, liquids and dry
materials can be effectively agglomerated into crisp, free flowing detergent
agglomerates having a
high density of at least 650 g/l. Moreover, such agglomeration processes have
produced detergent
agglomerates containing a wide range of particle sizes, for example "ovens"
and "fines" are typically
produced. The "ovens" or larger than desired agglomerate particles have a
tendency to decrease the
overall solubility of the detergent composition in the washing solution which
leads to poor cleaning
and the presence of insoluble "clumps" ultimately resulting in consumer
dissatisfaction. The "fines"
or smaller than desired agglomerate particles have a tendency to "gel" in the
washing solution and
also give the detergent product an undesirable sense of "dustiness." Further,
past attempts to recycle
such "ovens" and "fines" has resulted in the exponential growth of additional
undesirable over-sized
and under-sized agglomerates since the "ovens" typically provide a nucleation
site or seed for the
agglomeration of even larger particles, while recycling "fines" inhibits
agglomeration leading to the
production of more "fines" in the process.
Accordingly, there remains a need in the art for a process which produces a
high density
detergent composition having improved flow and particle size properties. Also,
there remains a
WO 96/09370 ~ ~ PCT/US95/11271
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need for such a process which is more eilicient and economical to facilitate
large-scale production of
low dosage or compact detergents.
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BACKGROUND ART
The following references are directed to densifying spray-dried granules:
Appel et al,
U.S. Patent No. 5,133,924 (Lever); Bortolotti et al, U.S. Patent No. 5,160,657
(Lever); Johnson
et al, British Patent rdo. 1,517,713 (Unilever); and Curtis, European Patent
Application 451,894.
The following references are directed to producing detergents by
agglomeration: Beerse et al,
U.S. Patent No. 5,108,646 (Procter & Gamble); Hollingsworth et al, European
Patent Application
351,937 (Unilever); and Swatting et al, U.S. Patent No. 5,205,958.
SUMMARY OF THE INVENTION
The present invention meets the aforementioned needs in the art by providing a
process
which continuously produces a high density detergent composition containing
agglomerates
directly from starting detergent ingredients. Consequently, the process
achieves the desired high
density detergent composition without unnecessary process parameters, such as
the use of spray
drying techniques and relatively high operating temperatures, all of which
increase manufacturing
costs. The process invention described herein also provides a detergent
composition containing
agglomerates having improved flow and particle size (i.e. more uniform)
properties which
ultimately results in a low dosage or compact detergent product having more
acceptance by
consumers. As used herein, the term "agglomerates" refers to particles formed
by agglomerating
starting detergent ingredients (liquid and/or particles) which typically have
a smaller median
particle size than the formed agglomerates. All percentages and ratios used
herein are expressed
as percentages by weight (anhydrous basis) unless otherwise indicated. All
viscosities referenced
herein are measured at 70°C (t5°C) and at shear rates of about
10 to 100 sec-~.
In accordance with one aspect of the invention, a pmcess for continuously
preparing
high density detergent composition is provided. The process comprises the
steps of (a)
continuously charging a detergent surfactant paste and dry starting detergent
material into a high
speed mixer/densifier to obtain agglomerates, wherein the mean residence time
in said high speed
mixer/densifler is from 2 seconds to 45 seconds; (b) mixing said agglomerates
in a moderate
speed mixer/densifler to further densify, build-up and agglomerate said
agglomerates such that
said agglomerates have a median particle size from 300 microns to 900 microns,
wherein the
mean residence time in said moderate speed mixer/densifler is from 0.5 minutes
to 15 minutes;
(c) feeding said agglomerates into a conditioning apparatus for improving the
flow properties of
said agglomerates and for separating said agglomerates into a first
agglomerate mixture and a
second agglomerate mixture, wherein said first agglomerate mixture
substantially has a particle
size of less than 150 microns and said second agglomerate mixture
substantially has a particle
size of at least 150 microns; (d) recycling said first agglomerate mixture
into said high speed
mixer/densifier for further agglomeration; (e) admixing adjunct detergent
ingredients to said
second agglomerate mixture so as to form said high density detergent
composition.
In accordance with anather aspect of the invention, another process for
continuously
preparing high density detergent composition is provided. This process
comprises the steps of
(a) continuously charging a detergent surfactant paste and dry starting
detergent material into a
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high speed mixer/densifier to obtain agglomerates, wherein the mean residence
time of said
agglomerates in said high speed mixer/densifier is from 2 seconds to 45
seconds; (b) mixing said
agglomerates in a moderate speed mixer/densifier to further densify, build-up
and agglomerate
said agglomerates such that said agglomerates have a median particle size from
300 microns to
900 microns, wherein the mean residence time of said agglomerates in said
moderate speed
mixer/densifier is from 0.5 minutes to 15 minutes; (c) screening said
agglomerates so as to form
a first agglomerate mixture substantially having a particle size of at least 6
mm and a second
agglomerate mixture substantially having a particle size of less than 6 mm;
(d) feeding said first
agglomerate mixture to a grinding apparatus and said second agglomerate
mixture to a
conditioning apparatus for improving the flow properties of said second
agglomerate mixture
and for separating said second agglomerate mixture into a third agglomerate
mixture and a
fourth agglomerate mixture, wherein said third agglomerate mixture
substantially has a particle
size of less than 150 microns and said fourth agglomerate mixture
substantially has a particle
size of at leasf 150 microns; (e) recycling said third agglomerate mixture
into said high speed
mixer/densifier for fiufiher agglomeration; (fj separating said fourth
agglomerate mixture into a
fifth agglomerate mixture and a sixth agglomerate mixture, wherein said fifth
agglomerate
mixture has a particle size of at least 900 microns and said sixth agglomerate
mixture has a
median particle size of from 50 microns to 1400 microns; (g) inputting said
fifth agglomerate
mixture into said grinding apparatus for grinding with said fn~st agglomerate
mixture to form a
ground agglomerate mixture which is recycled into said conditioning apparatus;
and (h) admixing
adjunct detergent ingredients to said sixth agglomerate mixture so as to form
said high density
detergent composition. Another aspect of the invention is directed to a high
density detergent
composition made according to any one of the embodiments of the instant
process.
Accordingly, it is an object of the invention to provide a pmcess which
produces a high
density detergent composition containing agglomerates having improved flow and
particle size
properties. It is also an object of the invention to provide such a process
which is more efficient
and economical to facilitate large-scale production of low dosage or compact
detergents. These
and other objects, features and attendant advantages of the present invention
will become
apparent to those skilled in the art from a reading of the following detailed
description of the
preferred embodiment and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a flow diagram of a process in accordance with one embodiment of the
invention in which undersized detergent agglomerates are recycled back into
the high speed
mixer/densifier from the conditioning apparatus; and
Fig. 2 is a flow diagram of a process in accordance with another embodiment of
the
invention similar to F:ig. 1 in which an additional recycling operation is
included for purposes of
further improving the properties of the resulting detergent product.
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DETAILED DESCRIPTION OF THE PREFERRED EIy)BODIIy>ENT
. Reference can be made to Figs. 1 and 2 for purposes of illustrating xveral
embodiments of
the process invention described herein. Fig. 1 illustrates a process IO while
Fig. 2 depicts a process
10' which is a modified version of process 10.
Process
Initially, the process '10 shown in Fig. 1 entails continuously charging a
detergent
surfactant paste 12 and dry starting detergent material 14 into a high speed
mixer/densifier ~16 to
obtain agglomerates 18. The various ingredients which may be selected for the
surfactant paste 12
and the dry starting detergent material 14 arc described more fully
hereinafter. However, it is
preferable for the ratio of the surfactant paste to the dry detergent material
to be from about 1:10 to
about 10:1 and more preferably from about 1:4 to about 4:1. The agglomerates
18 arc then xnt or
fed to a moderate speed mixer/densifier 20 to density and build-up further and
agglomerate the
agglomerates 18 such that they have the preferred median particle size range
of from about 300
microns to about 900 microns.
It should be understood that the dry starting detergent material 14 and
surfactant paste 12
begin to build-up into agglomerates in the high speed mixer/densifier 16, thus
resulting in the
agglomerates 18. The agglomerates 18 are then built-up further in the moderate
speed
mixer/densifier 20 resulting in further densified or built-up agglomerates 22
which arc ready for
further processing to increase their flow properties.
Typicxil apparatus used in process 10 for the high speed mixer/densi5er 16
include but are
not limited to a LtSdige "'' Recycler CB-30 while the moderate speed
mixer/densifier 20 can be a
LtSdige Recycler KM-G00 "PloughshareT"''". Other apparatus that may be used
include conventional
twin-screw mixers, mixers commercially sold as Eirich, Schugi, O'Hrie0. and
Drais mixers, and
combinations of thex and other mixers. Residence times of the
agglomerates/ingredients in such
mixer/densifiers will vary depending on the particular mixer/densifier and
operating parameters.
However, the.preferred residenx time in the high speed mixer/densiFer 16 is
from about 2 seconds
to about 45 seconds, preferably from about 5 to 30 seconds, while the
residence time in the moderate
speed mixer/densifier is from about 0.5 minutes to about 15 minutes,
preferably from about 1 to 10
minutes.
The moderate speed mixer/densifier 20 preferably imparts a requisite amount of
energy to
the agglomerates 18 for further build-up or agglomeration. More particularly,
the moderate speed
mixer/densifier 20 imparts from about 5 x 1010 erg/kg to about 2 x 1012 erg/kg
at a rate of from
about 3 x 108 erg/kg-xc to abort 3 x 109 erglkg-sec to form agglomerates 22.
The energy input
and rate of input can be determined by calculations from power readings to the
moderate speed
mixer/densifier 20 with and without agglomerates, residenx time of the
agglomerates, and the mass
of the agglomerates in the moderate speed mixer/densilier 20. Such
calculations are clearly within
the scope of the skilled artisan.
WO 96/09370 ~ ~ ~ ~ ~ ~ ~ PCT/US95/11271
_7_
Optionally, a coating agent can be added just before, in or after the
mixer/densifier 20 to
control or inhibit the degree of agglomeration. This optional step provides a
means by which the
desired agglomerate particle size can be achieved. Preferably, the coating
agent is selected from the
group consisting of aluminosilicates, carbonates, silicates and mixtures
thereof. Another optional
step entails spraying a binder material into the high speed mixer/densifier 16
so as to facilitate
build-up agglomeration. Preferably, the binder is selected from the group
consisting of water,
anionic surfactants, nonionic surfactants, polyethylene glycol, polyvinyl
pyrrolidone, polyacrylates,
citric acid and mixtures thereof.
Another step in the process 10 entails feeding the further densified
agglomerates 22 into a
conditioning apparatus 24 which preferably includes one or more of a drying
apparatus and a
cooling apparatus (not shown individually). The conditioning apparatus 24 in
whatever form (fluid
bed dryer, fluid bed cooler, airlift, etc.) is included for improving the flow
properties of the
agglomerates 22 and for separating them into a first agglomerate mixture 26
and a second
agglomerate mixture 28. Preferably, the agglomerate mixture 26 substantially
has a particle size of
less than about 150 microns and the agglomerate mixture 28 substantially has a
particle size of at
least about 150 microns. Of course, it should be understood by those skilled
in the art that such
separation processes are not always perfect and there may be a small protion
of agglomerate
particles in agglomerate mixture 26 or 28 which is outside the recited size
range. The ultimate goal
of the process 10, however, is to divide a substantial portion of the "fines"
or undersized
agglomerates 26 from the more desired sized agglomerates 28 which are then
sent to one or more
finishing steps 30.
The agglomerate mixture 26 is recycled back into the high speed
mixer/densifier 16 for
further agglomeration such that the agglomerates in mixture 26 are ultimately
built-up to the
desired agglomerate particle size. Preferably, the finishing steps 30 will
include admixing adjunct
detergent ingredients to agglomerate mixture 28 so as to form a fully
formulated high density
detergent composition 32 which is ready for commercialization. In a preferred
embodiment, the
detergent composition 32 has a density of at least 650 g/I. Optionally, the
finishing steps 30
includes admixing conventional spray-dried detergent particles to the
agglomerate mixture 28 along
with adjunct detergent ingredients to form detergent composition 32. In this
case, detergent
composition 32 preferably comprises from about 10% to about 40% by weight of
the agglomerate
mixture 28 and the balance spray-dried detergent particles and adjunct
ingredients.
Reference is now made to Fig. 2 which depicts process 10' for making a high
density
detergent composition in accordance with the invention. Similar to process 10,
the process 10'
comprises the steps of continuously charging a detergent surfactant paste 34
and dry starting
detergent material 36 into a high speed mixer/densifier 38 to obtain
agglomerates 40 and, mixing
the agglomerates 40 in a moderate speed mixer/densifier 42 to densify and
build-up further and
agglomerate the agglomerates 40 into agglomerates 44. The agglomerates 44
preferably have a
WO 96/09370 ~ ~ ~ ~ ~ ~ ~ PCT/US95/11271
_g_
median particle size from about 300 microns to about 900 microns. Thereafter,
the agglomerates 44
are screened in screening apparatus 46 so as to form a first agglomerate
mixture 48 substantially
having a particle size of at least about 6 mm and a second agglomerate mixture
50 substantially
having a particle size of less than about 6 mm. The agglomerate mixture 48
contains relatively wet
oversized agglomerates and usually represents about 2 to 5% of the
agglomerates 44 prior to
screening.
The agglomerate mixture 48 is fed to a grinding apparatus 52 while the
agglomerate
mixture 50 is fed to a conditioning apparatus 54 for improving the flow
properties of the
agglomerate mixture 50 and for separating the agglomerate mixture 50 into a
third agglomerate
mixture 56 and a fourth agglomerate mixture 58. Preferably, the agglomerate
mixture 56
substantially has a particle size of less than about 150 microns and the
agglomerate mixture 58
substantially has a particle size of at least 150 microns. The process 10'
entails recycling the
agglomerate mixture 56 back into the high speed mixer/densifier 38 for further
agglomeration as
described with respect to process 10 in Fig. 1. Thereafter, the agglomerate
mixture 58 is separated
via any known process/apparatus such as with conventional screening apparatus
66 or the like into a
fifth agglomerate mixture 60 and a sixth agglomerate mixture 62. Preferably,
the agglomerate
mixture 60 substantially has a particle size of at least 900 microns
(preferably larger than 1180
microns) and the agglomerate mixture 62 has a median particle size of from
about 50 microns to
about 1400 microns (preferably from about 50 microns to about 1180 microns).
The agglomerate mixture 60 which contains additional oversized agglomerate
particles is
inputted into the grinding apparatus 52 for grinding with the agglomerate
mixture 48 which also
contains oversized agglomerate particles to form a ground agglomerate mixture
64. Continuous
with the foregoing operations, the agglomerate mixture 64 is recycled back
into the conditioning
apparatus 54 which may include one or more fluid bed dryers and coolers as
described previously.
In such cases, the recycle stream of agglomerate mixture 64 can be sent to any
one or a combination
of such fluid bed dryers and coolers without departing from the scope of the
invention. The
agglomerate mixture 62 is then subjected to one or more finishing steps 68 as
described previously.
Preferably, the process 10' includes the step of admixing adjunct detergent
ingredients to the
agglomerate mixture 62 so as to form the high density detergent composition 70
which has a density
of at least 650 g/1.
The optional steps discussed with respect to the process 10 are equally
applicable with
respect to process 10'. By way of example, a coating agent can be added in or
after the moderate
speed mixerldensifier 42 to control or inhibit the degree of agglomeration. It
has been found that
adding a coating agent to the agglomerate mixture 62 or 58, i.e., before or
after between the
screening apparatus 66, yields a detergent composition with surprisingly
improved flow properties.
As mentioned previously, the coating agent is preferably selected from the
group consisting of
aluminosilicates, carbonates, silicates and mixtures thereof. The other
optional steps such as
CA 02199370 1999-06-23
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spraying a binder material into the high speed mixer/densifier 38 are useful
in process 10' for
purposes of facilitating build-up agglomeration. The residence times, energy
input parameters,
surfactant paste characteristics and ratios with starting dry detergent
ingredients are. all also
preferably incorporated into the process 10'.
Detereent Surfactant Paste
The detergent surfactant paste used in the processes 10 and 10' is preferably
in the form of
an aqueous viscous paste, although forms are also contemplated by the
invention. This so-celled
viscous surfactant paste has a viscosity of from about 5,000 cps to about
100,000 cps, more
preferably from about 10,000 cps to about 80,000 cps, and contains at least
about 10% water, more
preferably at least about 20% water. The viscosity is measured at 70°C
and at shear rates of about
10 to 100 sec.-1. Furthermore, the surfactant paste, if used, preferably
comprises a detersive
surfactant in the amounts specified previously and the balance water and other
conventional
detergent ingredients.
The surfactant itself. in the viscous surfactant paste, is preferably selxted
from anionic,
nonionic, zwitterionic, ampholytic and cationic classes and compatible
mixtures thereof. Detergent
surfactants useful herein are described in U.S. Patent 3,664,961, Norris,
issued May 23, 1972, and
in U.S. Patent 3,919,678, Laughlin et al., issued December 30, 1975. Useful
cationic surfactants
also include those described in U.S. Patent 4,222,905, Cockrell, issued
September 16, 1980, and in
U.S. Patent 4,239,659, Murphy, issued December 16, 1980. Of the surfactants,
avionics and
nonionics are preferred and avionics are most preferred.
Nonlimiting examples of the preferred anionic surfactants useful in the
surfactant paste
include the conventional C11-C18 alkyl benzene sulfonates ("LAS"), Primary,
bractchod-chain and
random C10-C20 ~yl ~~ ( '4S")~ ~ C10-C18 ~n~Y (2,3) alkyl sulfates of the
formula
CH3(CH2)x(CHOS03-M+) CH3 and CH3 (CH2)),(CHOS03-M+) Cli2CI~3 where x and (y +
1) are
inters of at least about 7, preferably at least about 9, and M is a water-
solubilizing canon,
especially sodium, unsaturated sulfates such as oleyl sulfate. and the C 10-C
18 alkyl alkoxy sulfates
("AExS"; apeciallY EO I 7 ethoxy sulfates).
Optionally, other exemplary s<trfxtartts useful in the paste of the invention
include
C10-C18 ~yl foxy carboxylates (esp~iallY the EO 1-5 ethoxycarboxylates), the
C10-18 g1Y°~I
ethers, the C10-C18 alkyl polyglyoosides and their corresponding sulfated
polyglycosidGS, and
C12'C18 ~P~-~o~ted fatty acid esters. If desired, the conventional nonionic
and amphoteric
surfactants such as the C12-C18 alkyl ethoxylates ("AE") including the so-
called marrow peaked
alkyl ethoxylates and C6-C 12 alkyl Phenol alkoxylates (espxially ethoxylates
and mixed
ethoxy/propoxy), C12-C18 betaines amd sulfobetaines ("sultaines"). Clp-C18
amine oxides, and the
like, can also be included in the overall compositions. The C 10-C 18 N-alkyl
polyhydroxy fatty acid
amides can also be used. Typical examples include the C 12-C 18
N'm~'Ylglucamides. See WO
CA 02199370 1999-06-23
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92/06154. Other sugar-derived surfactants include the N-alko.~ry polyhydroxy
fatty acid amides,
such. as Cl0-Clg N-(.3-methovypropyl) gluc~amide. The N-propyl through N-hexyl
C12-C18
glucamides can be used for low sudsing. C 10-C20 conventional soaps may also
be used, If >ugh
sudsing is desired, the branched-chain C10-C16 GPs may be used. Mixtures of
anionic ai,d
nonionic surfactants are especially useful. Other conventional useful
surfactants are listed in
standard texts.
Drv Detergent Material
The starting dry detergent material of the processes 10 and 10' preferably
comprises a
detergency builder xlected from the group consisting of aluminosilicates,
crystalline layered silicates
and mixtures thereof. and carbonate, preferably sodium carbonate. The
aluminosilicates or
aluminosilicate ion exchange materials used herein as a detergent builder
preferably have both a high
calcium ion exchange capacity and a high exchange rate. Without intending to
be limited by thoory. it
is believed that such high calcium ion exchange rate and capacity are a
function of severe! interrelated
factors which derive from the method by which the aluminosilicate ion exchange
material is produced.
In that regard, the aluminosilicate ion exchange materials used herein are
preferably produced is
accordance with Corkill et al, U.S. Patent No. 4,605,509 (Procter & Gamble).
Preferably, the aluminosilicate ion exchange material is in "sodium" form
since the potassium
and hydrogen forms of the instant aluminosilicate do not exhibit the as high
of an exchange rate and
capacity as provided by the sodium form. Additionally, the aluminosilicate ion
exchange material
preferably is in over dried form so as to facilitate production of crisp
detergent agglomerates as
described herein. The aluminosilicate ion exchange materials used herein
preferably have particle size
diameters which optimize their effoctivetkss as detergent builders. The term
"particle size diameter" as
used herein represents the average particle size diameter of a given
aluminosilicate ion exchange
material as determined by conventional analytical techniques, such as
microscopic determination and
scanning electron microscope (SEM). The preferred particle size diameter of
the aluminosilicate is
from about 0.1 micron to about 10 microns, more preferably from about 0.5
microns to about 9 microns.
Most preferably, the particle size diameter is from about 1 microns to about 8
microns.
Preferably. the aluminosilicate ion exchange material has the formula
Nazl(A102)z.(Si02~,]xH20 '
wherein z and y are integers of at least G, the molar ratio of z to y is from
about 1 to about 5 and x is
from about 10 to about 264. Mots preferably, the aluminosilicate has the
formula
Nal2[(A102)12.(St02)12]xH20
wherein x is from about 20 to about 30, preferably about 27. These preferred
aluminosilicates are
available commercially. for example under designations Z,eolite A, Zeolite 8
and Z.eolite X.
Alternatively, naturally.occurring or synthetically derived aluminosilicate
ion exchange materials
CA 02199370 1999-06-23
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suitable for use herein can be made as described in Krummel et al, U.S. Patent
No. 3,985,669.
The aluminosilicates used herein are further characterized by their ion
exchange capacity
which is at least about 200 mg equivalent of CaCO, hardness/gram, calculated
on an anhydrous
basis, and which is preferably in a range from about 300 to 352 mg equivalent
of CaCO,
hardness/gram. Additionally, the instant aluminosilicate ion exchange
materials are still further
characterized by their calcium ion exchange rate which is at least about 2
grains
Ca~/gallon/minute/gram/gallon, and more preferably in a range from about 2
grains
Ca~'"'/gallon/minute/gram/gallon to about 6 grains
Ca+'/gallon/minute/gram/gallon.
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Adjunct Detereent Ingredients
The starting dry detergent material in the present process can include
additional detergent
ingredients and/or, any number of additional ingredients can be incorporated
in the detergent
composition during subsequent steps of the present process. These adjunct
ingredients include other
detergency builders, bleaches, bleach activators, suds boosters or suds
suppressers, anti-tarnish and
anticorrosion agents, soi! suspending agents, soil release agents, germicides,
pH adjusting agents,
non-builder alkalinity sources, chelating agents, smectite clays, enzymes,
enzyme-stabilizing agents and
perfumes. See U.S. Patent 3,936,537, issued February 3, 1976 to Baskerville,
Jr. et al.
Other builders can be generally selected from the various water-soluble,
alkali metal,
ammonium or substituted ammonium phosphates, polyphosphates, phosphonates,
polyphosphonates, carbonates, berates, polyhydroxy sulfonates, polyaatates,
c~rboxylates, and
polycarboxylates. Preferred are the alkali metal, especially sodium, salts of
the above. Preferred for
use herein are the phosphates, carbonates, C10-18 fanf ~i~. polycarboxylates.
and mixtures
thereof. More preferred are sodium tripolyphosphate, tetrgsodium
pyrophosphate, citrate; tartrate
mono- and di-succinates, and mixtures thereof (see below).
In comparison with amorphous sodium silicates, crystalline layered sodium
silicates exhibit a
clearly increased calcium and magnesium ion exchange capacity. In addition,
the layered sodium
silicates prefer magnesium ions over calcium ions, a feature necessary to
insure that substantially all of
the "hardness" is removed from the wash water. These crystalline layered
sodium silicates, however,
are generally more expensive than amorphous silicates as well as other
builders. Accordingly, in order
to provide an economically feasible laundry detergent, the proportion of
crystalline layered sodium
silicates used must be determined judiciously.
The crystalline layered sodium silicates suitable for use herein preferably
have the formula
NaMSix02x+1 ~yH20
wherein M is sodium or hydrogen, x is from about 1.9 to about 4 and y is from
about 0 to about 20.
More preferably, the crystalline layered sodium silicate has the formula
NaMSi205.y820
wherein M is sodium or hydrogen, and y is from about 0 to about 20. These and
other crystalline
layered sodium silicates are discussed in Corkill et al, U.S. Patent No.
4,605,509.
Spxifrc examples of inorganic phosphate builders are sodium and potassium
tripolyphosphate, pyrophosphate, polymeric metaphosphate having a degcte of
polymerization of
from about 6 to 21, and orthophosphates. E.rcamples of polyphosphonate
builders are the sodium
and potassium salts of ethylene diphosphonic acid the sodium and potassium
salts of ethane
1-hydroxy-1, 1-diphosphonic acid and the sodium and potassium salts of ethane,
1,1,2-triphosphonic acid. Other phosphorus builder compounds are disclosed in
U.S. Patents
CA 02199370 1999-06-23
-13-
3,159,581; 3,213,030; 3,422,021; 3,422,137; 3,400,176 and 3,400,148.
Examples of nonphosphorus, inorganic builders are tetraborate decahydrate and
silicates
having a weight ratio of SiOz to alkali metal oxide of from about 0.5 to about
4.0, preferably
from about 1.0 to about 2.4. Water-soluble, nonphosphorus organic builders
useful herein include
the various alkali metal, ammonium and substituted ammonium polyacetates,
carboxylates,
polycarboxylates and polyhydroxy sulfonates. Examples of polyacetate and
polycarboxylate
builders are the sodium, potassium, lithium, ammonium and substituted ammonium
salts of
ethylene diamine tetraacetic acid, nitrilotriacetic acid, oxydisuccinic acid,
mellitic acid, benzene
polycarboxylic acids, and citric acid.
Polymeric polycarboxylate builders are set forth in U.S. Patent 3,308,067,
Diehl, issued
March 7, 1967. Such materials include the water-soluble salts of homo- and
copolymers of
aliphatic carboxylic acids such as malefic acid, itaconic acid, mesaconic
acid, fumaric acid,
aconitic acid, citraconic acid and methylene malonic acid Some of these
materials are useful as
the water-soluble anianic polymer as hereinafter described, but only if in
intimate admixture with
the non-soap anionic surfactant.
Other suitable polycarboxylates for use herein are the polyacetal carboxylates
described
in U.S. Patent 4,144,26, issued March 13, 1979 to Crutchfield et al, and U.S.
Patent 4,246,495,
issued March 27, 1979 to Crutchfield et al. These polyacetal carboxylates can
be prepared by
bringing together under polymerization conditions an ester of glyoxylic acid
and a
polymerization initiator. The resulting polyacetal carboxylate ester is then
attached to chemically
stable end groups to stabilize the polyacetal carboxylate against rapid
depolymerization in
alkaline solution, converted to the corresponding salt, and added to a
detergent composition.
Particularly prefeaed polycarboxylate builders are the ether carboxylate
builder compositions
comprising a combination of tartrate monosuccinate and tartrate disuccinate
described in U.S.
Patent 4,663,071, Bush et al., issued May 5, 1987.
Bleaching agents and activators are described in U.S. Patent 4,412,934, Chung
et al.,
issued November 1, 1983, and in U.S. Patent 4,483,781, Hartman, issued
November 20, 1984.
Chelating agents are also described in U.S. Patent 4,663,071, Bush et al.,
from Column 17, line
54 through Column 1.B, line 68. Suds modifiers are also optional ingredients
and are described in
U.S. Patents 3,933,672, issued January 20, 1976 to Bartoletta et al., and
4,136,045, issued
January 23, 1979 to Ciault et al.
Suitable smectite clays for use herein are described in U.S. Patent 4,762,645,
Tucker et
al, issued August 9, 1988, Column 6, line 3 through Column 7, line 24.
Suitable additional
detergency builders for use herein are enumerated in the aforementioned
Baskerville
CA 02199370 1999-06-23
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patent, Column 13, line 54 through Column 16, line 16, and in U.S. Patent
4,663,071, Bush et al,
issued May 5, 1987.
In order to make the present invention more readily understood, reference is
made to the
following examples, which are intended to be illustrative only and not
intended to be limiting in
scope.
EXAMPLE I
This Example illustrates the process of the invention which produces free
flowing, crisp,
high density detergent composition. Two feed streams of various detergent
starting ingredients are
continuously. fed, at a rate of 2800 kg/hr, into a Ltldige CB-30
mixer/densifier, one of which
comprises a surfactant paste containing surfactant and water and the other
stream containing
starting dry detergent material containing aluminosilicate and sodium
carbonate. The rotational
speed of the shaft in the L~dige CH~30 mixer/densifier is about 1400 rpm and
the mean residence
time is about 10 seconds. The agglomerates from the LBdige CB-30
mixer/densifier are
continuously fed into a LBdige KM-600 mixer/densifier for further
agglomeration during which the
mean residence time is about 6 minutes. The resulting detergent agglomerates
are then fed to
conditioning apparatus including a fluid bed dryer and then to a fluid bed
cooler, the mean
residence time being about 10 minutes and 15 minutes, respectively. The
undersized or °fine"
agglomerate particles (less than about I50 microns) from the fluid bed dryer
and cooler are recycled
back into the Ltfdige CB-30 mixer/densifying. A coating agent,
aluminosilicate, is fed immediately
after the LOdige KM-600 mixer/densifier but before the fluid bed dryer to
enhanx the flowability of
the agglomerates. The detergent agglomerates exiting the fluid bed cooler are
screened, after which
adjunct detergent ingredients arc admixed therewith to result in a fully
formulated detergent product
having a uniform particle size distribution. The composition of the detergent
agglomerates exiting
the fluid bed cooler is set forth in Table I below:
TABLE I
Component . ~/v WeiEbt
014-15 ~yl ~~~YI foxy sulfate 30.0
Aluminosilicate 37.8
Sodium carbonate 19.1
Misc. (water, perfume, etc.) 13~
100.0
The density of the agglomerates in Table I is 750 g/1 and the median particle
siu is 475 microns.
Adjunct liquid detergent ingredients including penfucnes, brighteners and
enzymes are
sprayed onto or admixed to the agglomerates/particles described above in the
finishing step to result
in a fully formulated finished detergent composition. The relative proportions
of the overall
5nished detergent composition produced by the process of instant process is
presented in Table II
below:
197 0
WO 96/09370 PCT/US95/11271
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TABLE II
I% weight)
Component
C14-15 ~kyl sulfate/C1,1_15 alkyl ethoay sulfate/C12 linear21.6
alkylbenzene sulfonate
Polyacrylate (MW=4500) 2.5
Polyethylene glycol (MW=4000) 1.~
Sodium Sulfate 6.9
Aluminosilicate 25.6
Sodium carbonate 17.9
Protease enzyme 0.3
Cellulase enzyme 0.4
Lipase enzyme 0.3
Minors (water, perfume, etc.) 22.8
100.0
The density of the detergent composition in Table II is 660 g/I.
EXAMPLE II
This Example illustrates another process in accordance with the invention in
which the
steps described in Example I are performed in addition to the following steps:
(1) screening the
agglomerates exiting the Lbdige KM-600 such that the oversized particles (at
least about 4 mm) are
sent to a grinder; (2) screening the oversized agglomerate particles (at least
about 1180 microns)
exiting the fluid bed cooler and sending those oversized particles to the
grinder, as well; and (3)
inputting the ground oversized particles back into the fluid bed dryer and/or
fluid bed cooler.
Additionally, a coating agent, aluminosilicate, is added between the fluid bed
cooler and the
finishing (admixing and/or spraying adjunct ingredients) steps. The
composition of the detergent
agglomerates exiting the fluid bed cooler is set forth in Table III below:
TABLE III
Component % Weight
C14-15 ~'1 s~ate/alkyl ethoxy sulfate 30.0
Aluminosilicate 37,g
Sodium carbonate 19.1
Misc. (water, perfume, etc.) 13.1
100.0
The density of the agglomerates in Table I is 750 g/1 and the median particle
size is 425 microns.
The agglomerates also surprisingly have a more narrow particle size
distribution, wherein more
than 90% of the agglomerates have a particle size between about 150 microns to
about 1180
WO 96/09370 ,v 2 ~ g g 3 '7 ~ PCT/US95/11271
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microns. This result unexpectedly matches the desired agglomerate particle
size distribution (i.e. all
agglomerates below 1180 microns) more closely.
Adjunct liquid detergent ingredients including perfumes, brighteners and
enzymes are
sprayed onto or admixed to the agglomerates/particles described above in the
finishing step to result
in a fully formulated finished detergent composition. The relative proportions
of the overall
finished detergent composition produced by the process of instant process is
presented in Table IV
below:
TABLE IV
(% weight)
Component B
C 14-15 ~kyl sulfate/C 14_ 15 alkyl ethoxy21.6
sulfate/C 12 linear
alkylbenzene sulfonate
Polyacrylate (MW=4500) 2.5
Polyethylene glycol (MW=4000) 1.7
Sodium Sulfate 6.9
Aluminosilicate 25.6
Sodium carbonate 17.9
Protease enzyme 0.3
Cellulase enzyme 0.4
Lipase enzyme 0.3
Minors (water, perfume, etc.) 2
100.0
The density of the detergent composition in Table IV is 660 g/1.
Having thus described the invention in detail, it will be clear to those
skilled in the art that
various changes may be made without departing from the scope of the invention
and the invention is
not to be considered limited to what is described in the specification.
